Apparatus for cutting grooves in record-disks



B. SCHIFFMAN APPARATUS FOR CUTTING GROOVES IN RECORD DISKS.

APPLICATION men APR.23. 1915.

1,195,101. Patented Aug. 15, 1916.

WlT/VESSES: I/V VE/VTOR Aaer/ Sc/u'ffman.

A TTOR/VE Y ROBERT SCHIFFMAN, OF TOLEDO, OHIO.

APPARATUS FOR CUTTING GROOVES IN RECORD-DISKS.

Specification of Letters Patent.

Patented Aug. 15, 1918.

Application filed Apri1 23, 1915. Serial No. 23,356.

To all whom it may concern:

Be it known that I, ROBERT SCHIFFMAN, a citizen of the United States, and a resident ,:;*}-of Toledo, in the county of Lucas and State of Ohio, have invented a new and Improved Apparatus for Cutting Grooves in Record- Disks, of which the following is a full, clear, and exact description.

Among the principal objects which the present lnvention has in view are: to provide means for adding a circular groove to a recorddisk for a talking machine, and means for rapidly transferring the needle of a talking machine from the'record groove to said circular groove; to provide means for adjusting the apparatus to record disks of different diameters; to provide means for regulating the diameter of said circular grooves; and to provide means for facilitating the cutting of said circular groove anda switch groove connecting the same with the record groove.

Drawings.-Figure 1 is a top plan view of an apparatus constructed and arranged in accordance with the present invention, showing in conjunction therewith a talking machine record disk; and Fig. 2 is a side elevation of the same.

Description-As seen in the accompanying drawings, a scribing plate 8 has a per foration 9 adapted to fit over and obtain bearing upon a centering pin 10 which in the present invention is centrally located in a rotatable table 11. The pin 10 corresponds with the centering pin employed in the rotar table of the talking machine. The scribing plate 8 has an exterior ruling edge, said edge being spirally formed to a regularly diminishing curve, said curve extending from the exterior angle 13 to the interior angle 14, as best shown in Fig. 1 of the drawings. From the plate 8 is extended a gage member. The member 15 is shaped to form the gage edges 16 and 17. The edges 16 and 17 correspond with the edges of ten-inch and twelve-inch record disks. The clamp 18 is U-shaped and one arm of the clamp is tapped to engage the threads of a screw 19. It is obvious that in service the clamp 18 may be shifted to engage a twelve-inch or a ten-inch record disk.

The cutting or grooving which is performed by means of the present apparatus, on the record disk, such as indicated in the drawings by the'numeral 20, is effected by the stylus 21. The stylus 21 is mounted, in service, in a chuck 22 of any convenient type. The chuck shown in the. drawings employs a set screw 23 for holding the stylus 21 rigid in service. The chuck 22 is formed at the end of a swinging arm 24. The arm 24 is pivotally mounted on the standard 25 erected upon a base plate 26 as shown in Fig. 2 of the drawings. The base plate 26 also provides the turret 27 from which extends the pin 10.

The groove 28 is herein termed the stopping groove. It is circular in form being designed to hold a needle of a reproducer and the sound box connected therewith from traveling to or from the center of the record disk 20. It is desired that this stopping groove should be as close to the inner convolution 29 of the record groove as possible. To this end, the edge of the plate 8 is spirally shaped. At the inner terminus of the said edge in the angle '14 an arm 30 is mounted by the pivot 81 on the plate 8 to extend beyond the edge thereof. As the said arm is swung to and from the angle 14, it operates to hold the stylus 21 in the angle formed by said arm and the edge of the plate. The distance from the center of the plate or of the pin 10 increases as the arm 30 is moved away from the angle 14. By adjusting the arm 30, the angle formed thereby with the edge of the plate, may be arranged to hold the stylus in closer relation to the inner convolution of the groove 29.

Operation-Having an apparatus constructed and arranged as described and shown in the accompanying drawings, the operation as performed upon a record disk is as follows: The disk 20 is first disposed on the table 11. The disk having been centered by means of the pin 10, the scribing plate 8 is superposed thereon, the perforation 9 receiving the said pin 10. It having been ascertained that the record disk is a ten or a twelve-inch disk, the clamp 18 is shifted to accommodate the same, the plate 8 being thereby secured rigidly in position upon said record disk. The arm 30 is moved on its pivot 31 until the angle formed thereby with the edge of the plate 8 registers with reference to the last convolution of the record groove 29. The arm 30 is maintained in its adjusted position by small abutments 32, which extend upward from the surface of the plate 8 to hold the arm 30 during the formation of the stop groove by the stylus 21.

The arm 24 is swung over the record disk' 20 until the stylus 21 strikes upon the ruling edge 12 of the plate 8. The disk 20 is shifted until the intersection of th last convolution of the record groove of he disk, and the ruling edge 12 of the plate 8 registers with the position of the stylus 21. Pressure is applied to the chuck 22 and stylus 21 therein, while the disk 20 and table 11 are slowly' rotated clockwise. The pressure which is applied to the stylus 21 holds the same upon the record and simultaneously maintains the same againstthe edge 12 of I the plate 8. In the course of the rotation of the disk 20 and plate 8, the stylus 21 is engaged by the arm 30.. The screw 19 and the clamp 18 is then released. The operator now holds the arm 30, plate 8 and stylus 21 fixedly, while he turns the table 11, and the record disk 20 thereon. This results in cutting by means of the stylus 21, a complete circular groove. When record disks thus prepared are placed upon the rotary table of a talking machine it will be found that when the record needle reaches the end of the record groove it passes through the relatively short switch grooves formed to the curvature of the ruling edge 12, to the circular or stopping grooves 28. If the machine is not then arrested it will be found that the reproducing needle runs around the circular groove 28, the sound box and tone tube of the talking machine being thereby groove on said disk, said means embodying a perforation concentric with the axis of said marking edge, and a lateral extension of said plate, said extension exceeding in length the radius of the record disk; a swinging arm pivotally mounted beyond the area occupied by said record disk; means disposed at the free end of said arm for holding a cutting stylus; a cutting stylus held by said means inoperative relation to a record disk; a stylus engaging arm adjustably mounted on said plate and extending beyond the marking edge thereof, said arm being adapted for forming angles with said plate at different points on said edge,

said angles being variously distant from said perforation; and means for holding said arm in adjusted position.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ROBERT SCHIFF MAN.

Witnesses:

WILLIAM F. JACOB, FRED SGHIFFMAN. 

